Gaps of the Allegheny
The gaps of the Allegheny, meaning gaps in the Allegheny Ridge (now given the technical name Allegheny Front) in west-central Pennsylvania, is a series of escarpment eroding water gaps (notches or small valleys) along the saddle between two higher barrier ridge-lines in the eastern face atop the Allegheny Ridge or Allegheny Front escarpment. The front extends south through Western Maryland and forms much of the border between Virginia and West Virginia, in part explaining the difference in cultures between those two post-Civil War states.